The present invention relates to apparatus for producing and processing a continuous layer of fibrous particles, especially to improvements in distributors for shredded tobacco, and more particularly to improvements in apparatus which can be used in machines for the making of wrapped rod-like tobacco fillers as a means for converting a mass of tobacco shreds into a homogenized tobacco layer of uniform height and width so that the layer can be readily converted into a narrow tobacco stream.
The distributor of a cigarette rod making machine normally comprises a magazine for a supply of shredded tobacco, a carded drum which draws a continuous layer of tobacco particles from the magazine, means for segregating lightweight particles of the layer from heavier tobacco particles and for assembling the lightweight particles into a wide carpet or sliver, and means for showering or propelling the leading edge of the carpet into a narrow channel to form a continuous tobacco stream.
It was already proposed to enhance the homogeneousness of the layer which is being withdrawn from the magazine of a distributor for shredded tobacco by subjecting the layer to a series of smoothing, combing, compacting and surplus-removing treatments. Such treatments are expensive because they are carried out by resorting to relatively complex equipment having a substantial number of discrete units and occupying a substantial amount of space. Also, the just described treatment cannot invariably guarantee the formation of a tobacco layer which can be converted into a filler without any further treatment, especially without trimming by one or more sets of knives or analogous equalizing devices. Still further, the just described treatment does not guarantee the formation of a layer which is free of holes or gaps and wherein the homogenization is effected without any or with minimal comminution of tobacco shreds.
My copending application Ser. No. 536,302 discloses a distributor wherein the layer of tobacco shreads which is being withdrawn from a magazine by the carding of a rotary drum is equalized by novel homogenizing means which is preferably immediately or closely adjacent to the outlet opening of the magazine. The homogenizing means comprises a preferably strip-shaped barrier having a preferably profile (e.g., grooved) first surface which is adjacent to and in contact with the exposed side of the tobacco layer on the carded drum, and a second surface which is adjacent to the first surface and extends substantially transversely of the layer and faces toward the outlet of the magazine, i.e., counter to the direction of transport of the layer, whereby at least some particles of the layer which extend beyond the first surface are intercepted by and pile up at the second surface of the barrier. The homogenizing means further comprises means for moving the barrier back and forth substantially transversely of the path of movement of the layer so that the first surface of the barrier reciprocates along the exposed side of the layer, and a paddle wheel or analogous refuser means for moving the piled-up particles counter to the direction of movement of the layer, preferably directly back into the magazine.
The advantages of the just described homogenizing means can be summarized as follows:
The material which is being continuously withdrawn from the magazine is converted into a homogeneous layer in a small area, by resorting to a small number of simple instrumentalities and without any or with negligible comminution of tobacco shreds. The simple instrumentalities of the homogenizing means perform functions which are performed in conventional distributors by a larger number of bulkier, more complex and more expensive components. The homogenizing means can be installed in existing distributors of cigarette rod making or analogous machines.